The Atlas of Macromolecular Structure on Microfiche (AMSOM) was published in March of 1977. About 100 copies are now being used by scientists all over the world. Each copy consists of an index volume which directs the user to the 650 microfiche and a stereo box with its related pair of stereo glasses. Because any microfiche viewer can be used the scientist population to which AMSOM was directed has had little trouble getting down to serious use. Early reports indicate that AMSOM will be heavily used to make systematic studies of the environmental contexts of various amino acids as well as the variations in the configuration of secondary structure units (alpha helices and beta sheets). Preparation of the first supplement is under way with about 40 new structure states available. A structure state suitable for inclusion in the supplement can be either a new structure or a refinement of a structure included in the first edition of the atlas. In addition, the scope of the atlas has been expanded to include small circular polypeptides and a new class of theoretically determined structures. Over seventy new crystal structure studies have been identified for the supplement. The supplement should be the same size as the first edition when it is published in 1978. This conforms with the expected exponential rate of increase of both new structure states and new crystallization studies.